I would like to throw in my two cents about armour.
I do renaissance fencing, and the techniques vary a lot based on the protection the oponent is wearing, so I would like to give a relative breakdown of how effective those are (may not be news to you guys, but blew my mind after playing dnd for years).
A quilted gambeson is effective against some sword chopping blows, it would take a decently powerful strike with a sharp part of the blade to penetrate, or a thrust.
Maille would protect the user from chopping attacks until the maille fractured, and the wearer would take the blunt force damage from the blade if the maille didn't fracture.
Plate harness was essentially invulnerable to all but pole arms and projectiles. Poleaxes (smallish polearms) would be able to deal blunt trauma to the wearer, but if the attacker had a sword they would have to resort to finding seems in the armour to get through.
Not sure if that is any help to the predicament, but the idea of destructible armour or armour that you just can't get through without changing your tactics is really intriguing to me.
I also really like the idea of armour becoming obsolete. If you can afford some boiled leather vs raw hide, then nothing would be stopping you!
It might add an interesting economic effect to the game, you find some barbarians that can't afford to trade for good armour, or some militia that can only quilt their own gambeson's etc.